What follows is some guidance on the content and format expected of the required EOS instrument team Validation Plans. The definition of "validation" adopted by the EOS Panel on Data Quality is as follows:

Validation is the responsibility of the algorithm providers. It involves specification of the transformations required to extract estimates of high-level geophysical quantities from calibrated basic instrument measurables and specification of the uncertainties in the high-level geophysical quantities. Validation requires detailed knowledge of the relationship between measurables and geophysical quantities of interest over the full range of possible conditions. Pre-launch activities include determination of algorithms and characterization of uncertainties resulting from parameterizations and their algorithmic implementation. Post-launch activities include refinement of algorithms and uncertainty estimates based on near-direct comparisons with correlative data and selected, controlled analyses.

It is important that the characterization be as quantitative and as phenomenologically specific as possible to be truly useful to the science user, i.e., dependencies on sampling geometry, target scene, etc. For example, knowing that a certain derived parameter has a global root mean square uncertainty of x is not nearly as useful as knowing that the uncertainty is y < x under most situations but z > x in some other subset of conditions. To the extent possible, validation plans should attempt to assess data quality over the full range of expected conditions and phenomena.

A useful and natural partition of validation issues (that will be used for the Validation Workshops) is:

• Vicarious calibration and validation of the radiance data products,
• Validation of the higher-order geophysical data products.

The Science Data Validation Plans must address each of these separate aspects. Further grouping of interdependent data products, especially those sharing a common approach to validation, is also encouraged. However, each specific geophysical parameter contained within the data product should be identified and briefly described. While complete validation of the full hierarchy of processing products may not be essential or possible, identification of the critical path for validation of the scientific integrity of the higher order products is absolutely paramount.

Given the launch schedule, it is very important that the validation plan substantively describe planned post-launch validation activities in addition to planned pre-launch activities. With regard to the time period, the validation plans need to describe post-launch activities out to at least two years after launch. While general guidelines about the team's expectations beyond that time period are desired, detailed planning would become more speculative and less meaningful. As things begin to settle down after launch, probably about a year, we expect the teams will revise and extend their plans.

The Science Data Validation Plan must:

• Describe the approaches for establishing scientific validity,
• Describe how accuracy, precision and resolution will be defined and confirmed,
• List required EOS and non-EOS experimental activities,
• List required operational measurements, and
• Describe archival plans for validation information.

Please view the proposed outline for an EOS instrument team Science Data Validation Plan. The Project Science Office expects all teams to generally adhere to this outline. While the fit will not be perfect in all cases, the imposed commonality will greatly aid in the review and integration process. Furthermore, each team should recognize and adhere to the policy that archival of and open access to its validation data is absolutely essential!

It is imperative that the validation process be well-defined. Very specific information is needed for items (3) and (4) above. Field activities that are to be executed in conjunction with known national or international field programs should be identified. Sufficient detail should be given so that other planned elements can be associated with presently unknown opportunities for cooperative field experiments. It is particularly important to identify critical external resources that will be required, e.g., networks of surface instrumentation that are clearly beyond the means of any individual team but which would likely have application for a number of teams. Team-specific elements where funding augmentations will be necessary to accomplish the required activity (e.g., flight hours) should be described, costed and prioritized. In addition, elements that are beyond present technical and/or resource capabilities of the team, but which the team regards as required validation activities and which might be addressed by some other EOS entity (e.g., IDS teams or investigations selected through Validation NRAs) or non-EOS entity should also be clearly identified and prioritized. The Validation Plan must specify and describe what needs to be done, including what the team will do and what potentially could be done by or in cooperation with others.

The Project Science Office expects each instrument team to have and express a reasonable understanding of the priority and funding of all its planned validation activities, including its expected synergism with other related (non-EOS funded) activities of the team members.

It is expected that team validation plans will evolve right up until the time of launch and even thereafter. It is important for all parties to be able to quickly get a grasp on specifics of the current plans. This includes team members, members of other instrument and IDS teams, the Project Science Office (Senior Project Scientist and Validation Scientist), NASA Headquarters (Program Scientists) and the scientific community at large. Information will be the key to facilitating cooperation and collaboration, maximizing the scientific return while minimizing the cost. The mechanism that will be used to convey the most current information is the team Validation Plan Summary Charts. These charts will be updated quarterly, as appropriate, and will bridge the gap between development of the initial full Validation Plan and the final pre-launch revision to that plan (see Validation Planning Schedule). Such summaries will also be highly useful in facilitating the initial review and integration process, including the planned validation workshop.

Thus, we request that you please prepare and submit a set of charts summarizing your validation plan (as a separate document). The Validation Summary Charts should specifically list the data products including vicarious calibration and validation of radiance data products and validation of the higher order data products. Logical grouping of data products, especially those sharing a common approach to validation, is highly encouraged. An integrated presentation is clearly superior to a piecemeal approach. The charts should:

• Summarize the approaches for establishing scientific validity,
• Summarize how accuracy, precision and resolution will be confirmed,
• List required EOS and non-EOS experimental activities,
• List required operational measurements, and
• Outline the archival plans for validation information.

These will be distributed to all participants prior to the workshop. Recall that the purpose of the workshop is to facilitate the formation of appropriate partnerships and coordination of planned validation activities among the various instrument teams and, very importantly, to fully engage the IDS teams in planned validation activities, as well as to help the Project Science Office in formulating the upcoming NRA. These should be key considerations in preparation of the summary charts. It is especially important to indicate priority, resources and needs (people, things, funding), gaps, connections (intra/inter-team, programmatic, etc.), and schedule (dates).